Stenobrachius nannochir nannochir 



(Gilbert, 1890) 



Fig. 150 — Stenobrachius n. nannochir , female, 107.0 mm. 



Fig. 151 — Stenobrachius n. nannochir, drawing of specimen in Fig. 150. 



Description 



D. 14 (13); A. 15 (14-16); P. 9 (10); AO 7 (6-8); total 13-14 (15); gill rakers 5-6 + 1 + 12 

 (11-13), total 18-19 (17-20); vertebrae 37 (36-38). 



Size: To about 110 mm. 



Least depth of capture: To 300 m in daylight (See Discussion). 



Distribution: In the eastern Pacific this is a more northern form than S. leucopsarus . Off 

 California it is not taken south of about 40° N; it ranges north into Gulf of Alaska and across 

 the North Pacific (Fig. 149). A subspecies, S. n. laticauda Kulikova (1960), occurs in Okhotsk 

 Sea, but the eastern range of this subspecies, or any overlap in distribution of the two forms, is 

 not known. 

 Discussion 



S. n. nannochir and its congener S. leucopsarus are somewhat similar and have been 

 confused although they are readily separable. In addition to the principal characters given in 

 the key to species, the following may be of aid in distinguishing between the two; In general, S. 

 leucopsarus has a more robust body; the depth at pectoral origin is 21% of SL, vs about 19% in 

 S. n. nannochir . The eye is slightly smaller and the upper jaw distinctly longer in S. n. 

 nannochir, such that the eye is 30% (28-33% ) of upper jaw vs 38% (34-41% ) in S. leucopsarus . 

 Also, the caudal peduncle is more slender '\nS. n. nannochir , its least depth being 30% 

 (28-33%r ) of its length vs 36% (33-40% ) in S. leucopsarus. 



In life, and persisting for some time in preservative, the photophores of S. leucopsarus are 

 yellowish-green in color, and those of S. n. nannochir claret. 



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